The present invention relates to a base frame for a gas turbine and optional driven machinery such as generators and the like, which base frame includes a centrally arranged hollow section which acts as a torsion-absorbing body, sections or wings which extend from the hollow section and form an angle of approximately 90.degree. with the longitudinal axis of the hollow section, one or more plate-shaped bodies arranged to cover wholly or partly the hollow section and the sections, where between the plate-shaped bodies, the sections and the hollow section there is formed at least one chamber on each side of the longitudinal axis of the hollow section.